Hybrid maize plant and seed (32K61)

ABSTRACT

According to the invention, there is provided a hybrid maize plant, designated as 32K61, produced by crossing two Pioneer Hi-Bred International, Inc. proprietary inbred maize lines. This invention relates to the hybrid seed 32K61, the hybrid plant produced from the seed, and variants, mutants, and trivial modifications of hybrid 32K61.

FIELD OF THE INVENTION

This invention is in the field of maize breeding, specifically relating to a hybrid maize line designated 32K61.

BACKGROUND OF THE INVENTION Plant Breeding

Field crops are bred through techniques that take advantage of the plant's method of pollination. A plant is self-pollinated if pollen from one flower is transferred to the same or another flower of the same plant. A plant is cross-pollinated if the pollen comes from a flower on a different plant.

Plants that have been self-pollinated and selected for type for many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny. A cross between two different homozygous lines produces a uniform population of hybrid plants that may be heterozygous for many gene loci. A cross of two plants each heterozygous at a number of gene loci will produce a population of hybrid plants that differ genetically and will not be uniform.

Maize (Zea mays L.), often referred to as corn in the United States, can be bred by both self-pollination and cross-pollination techniques. Maize has separate male and female flowers on the same plant, located on the tassel and the ear, respectively. Natural pollination occurs in maize when wind blows pollen from the tassels to the silks that protrude from the tops of the ears.

The development of a hybrid maize variety involves three steps: (1) the selection of plants from various germplasm pools for initial breeding crosses; (2) the selfing of the selected plants from the breeding crosses for several generations to produce a series of inbred lines, which, although different from each other, breed true and are highly uniform; and (3) crossing the selected inbred lines with unrelated inbred lines to produce the hybrid progeny (F₁). During the inbreeding process in maize, the vigor of the lines decreases. Vigor is restored when two different inbred lines are crossed to produce the hybrid progeny (F₁). An important consequence of the homozygosity and homogeneity of the inbred lines is that the hybrid created by crossing a defined pair of inbreds will always be the same. Once the inbreds that create a superior hybrid have been identified, a continual supply of the hybrid seed can be produced using these inbred parents and the hybrid corn plants can then be generated from this hybrid seed supply.

Large scale commercial maize hybrid production, as it is practiced today, requires the use of some form of male sterility system which controls or inactivates male fertility. A reliable method of controlling male fertility in plants also offers the opportunity for improved plant breeding. This is especially true for development of maize hybrids, which relies upon some sort of male sterility system. There are several options for controlling male fertility available to breeders, such as: manual or mechanical emasculation (or detasseling), cytoplasmic male sterility, genetic male sterility, gametocides and the like.

Hybrid maize seed is typically produced by a male sterility system incorporating manual or mechanical detasseling. Alternate strips of two inbred varieties of maize are planted in a field, and the pollen-bearing tassels are removed from one of the inbreds (female) prior to pollen shed. Providing that there is sufficient isolation from sources of foreign maize pollen, the ears of the detasseled inbred will be fertilized only from the other inbred (male), and the resulting seed is therefore hybrid and will form hybrid plants.

The laborious, and occasionally unreliable, detasseling process can be avoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMS inbred are male sterile as a result of factors resulting from the cytoplasmic, as opposed to the nuclear, genome. Thus, this characteristic is inherited exclusively through the female parent in maize plants, since only the female provides cytoplasm to the fertilized seed. CMS plants are fertilized with pollen from another inbred that is not male-sterile. Pollen from the second inbred may or may not contribute genes that make the hybrid plants male-fertile. Usually seed from detasseled fertile maize and CMS produced seed of the same hybrid are blended to insure that adequate pollen loads are available for fertilization when the hybrid plants are grown.

There are several methods of conferring genetic male sterility available, such as multiple mutant genes at separate locations within the genome that confer male sterility, as disclosed in U.S. Pat. Nos. 4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations as described by Patterson in U.S. Pat. No. 3,861,709 and 3,710,511. These and all patents referred to are incorporated by reference. In addition to these methods, Albertsen et al., of Pioneer Hi-Bred, U.S. patent application Ser. No. 07/848,433, have developed a system of nuclear male sterility which includes: identifying a gene which is critical to male fertility; silencing this native gene which is critical to male fertility; removing the native promoter from the essential male fertility gene and replacing it with an inducible promoter; inserting this genetically engineered gene back into the plant; and thus creating a plant that is male sterile because the inducible promoter is not "on" resulting in the male fertility gene not being transcribed. Fertility is restored by inducing, or turning "on", the promoter, which in turn allows the gene that confers male fertility to be transcribed.

There are many other methods of conferring genetic male sterility in the art, each with its own benefits and drawbacks. These methods use a variety of approaches such as delivering into the plant a gene encoding a cytotoxic substance associated with a male tissue specific promoter or an antisense system in which a gene critical to fertility is identified and an antisense to that gene is inserted in the plant (see: Fabinjanski, et al. EPO 89/3010153.8 publication no. 329,308 and PCT application PCT/CA90/00037 published as WO 90/08828).

Another system useful in controlling male sterility makes use of gametocides. Gametocides are not a genetic system, but rather a topical application of chemicals. These chemicals affect cells that are critical to male fertility. The application of these chemicals affects fertility in the plants only for the growing season in which the gametocide is applied (see Carlson, Glenn R., U.S. Pat. No.: 4,936,904). Application of the gametocide, timing of the application and genotype specificity often limit the usefulness of the approach.

The use of male sterile inbreds is but one factor in the production of maize hybrids. The development of maize hybrids requires, in general, the development of homozygous inbred lines, the crossing of these lines, and the evaluation of the crosses. Breeding programs combine the genetic backgrounds from two or more inbred lines or various other broad-based sources into breeding pools from which new inbred lines are developed by selfing and selection of desired phenotypes. The new inbreds are crossed with other inbred lines and the hybrids from these crosses are evaluated to determine which of those have commercial potential.

There are many important factors to be considered in the art of plant breeding, such as the ability to recognize important morphological and physiological characteristics, the ability to design evaluation techniques for genotypic and phenotypic traits of interest, and the ability to search out and exploit the genes for the desired traits in new or improved combinations.

The objective of commercial maize hybrid line development programs is to develop new inbred lines to produce hybrids that combine to produce high grain yields and superior agronomic performance. The primary trait breeders seek is yield. However, many other major agronomic traits are of importance in hybrid combination and have an impact on yield or otherwise provide superior performance in hybrid combinations. Such traits include percent grain moisture at harvest, relative maturity, resistance to stalk breakage, resistance to root lodging, grain quality, and disease and insect resistance. In addition, the lines pe se must have acceptable performance for parental traits such as seed yields, kernel sizes, pollen production, all of which affect ability to provide parental lines in sufficient quantity and quality for hybridization. These traits have been shown to be under genetic control and many if not all of the traits are affected by multiple genes.

Pedigree Breeding

The pedigree method of breeding is the mostly widely used methodology for new hybrid line development.

In general terms this procedure consists of crossing two inbred lines to produce the non-segregating F₁ generation, and self pollination of the F₁ generation to produce the F₂ generation that segregates for all factors for which the inbred parents differ. An example of this process is set forth below. Variations of this generalized pedigree method are used, but all these variations produce a segregating generation which contains a range of variation for the traits of interest.

EXAMPLE 1 Hypothetical Example of Pedigree Breeding Program

Consider a cross between two inbred lines that differ for alleles at six loci. The parental genotypes are:

Parent1 AbCdeF/AbCdeF

Parent2 aBcDEf/aBcDEf

the F₁ from a cross between these two parents is:

F₁ AbCdeF/aBcDEf

Selfing F₁ will produce an F₂ generation including the following genotypes:

ABcDEf/abCdeF

ABcDef/abCdEF

ABcDef/abCdeF

The number of genotypes in the F₂ is 3⁶ for six segregating loci (729) and will produce (2⁶)-2 possible new inbreds, (62 for six segregating loci).

Each inbred parent which is used in breeding crosses represents a unique combination of genes, and the combined effects of the genes define the performance of the inbred and its performance in hybrid combination. There is published evidence (Smith, O. S., J. S. C. Smith, S. L. Bowen, R. A. Tenborg and S. J. Wall, TAG 80:833-840 (1990)) that each of the lines are different and can be uniquely identified on the basis of genetically-controlled molecular markers.

It has been shown (Hallauer, Arnel R. and Miranda, J. B. Fo. Quantitative Genetics in Maize Breeding, Iowa State University Press, Ames Iowa, 1981) that most traits of economic value in maize are under the genetic control of multiple genetic loci, and that there are a large number of unique combinations of these genes present in elite maize germplasm. If not, genetic progress using elite inbred lines would no longer be possible. Studies by Duvick and Russell (Duvick, D. N., Maydica 37:69-79, (1992); Russell, W. A., Maydica XXIX:375-390 (1983)) have shown that over the last 50 years the rate of genetic progress in commercial hybrids has been between one and two percent per year.

The number of genes affecting the trait of primary economic importance in maize, grain yield, has been estimated to be in the range of 10-1000. Inbred lines which are used as parents for breeding crosses differ in the number and combination of these genes. These factors make the plant breeder's task more difficult. Compounding this is evidence that no one line contains the favorable allele at all loci, and that different alleles have different economic values depending on the genetic background and field environment in which the hybrid is grown. Fifty years of breeding experience suggests that there are many genes affecting grain yield and each of these has a relatively small effect on this trait. The effects are small compared to breeders' ability to measure grain yield differences in evaluation trials. Therefore, the parents of the breeding cross must differ at several of these loci so that the genetic differences in the progeny will be large enough that breeders can develop a line that increases the economic worth of its hybrids over that of hybrids made with either parent.

If the number of loci segregating in a cross between two inbred lines is n, the number of unique genotypes in the F₂ generation is 3^(n) and the number of unique inbred lines from this cross is {(2^(n))-2}. Only a very limited number of these combinations are useful. Only about 1 in 10,000 of the progeny from F₂ 's are commercially useful.

By way of example, if it is assumed that the number of segregating loci in F₂ is somewhere between 20 and 50, and that each parent is fixed for half the favorable alleles, it is then possible to calculate the approximate probabilities of finding an inbred that has the favorable allele at {(n/2)+m} loci, where n/2 is the number of favorable alleles in each of the parents and m is the number of additional favorable alleles in the new inbred. See Example 2 below. The number m is assumed to be greater than three because each allele has so small an effect that evaluation techniques are not sensitive enough to detect differences due to three or less favorable alleles. The probabilities in Example 2 are on the order of 10⁻⁵ or smaller and they are the probabilities that at least one genotype with (n/2)=m favorable alleles will exist.

To put this in perspective, the number of plants grown on 60 million acres (approximate United States corn acreage) at 25,000 plants/acre is 1.5×10¹².

EXAMPLE 2 Probability of finding an inbred with m of n favorable alleles.

Assume each parent has n/2 of the favorable alleles and only 1/2 of the combinations of loci are economically useful.

    ______________________________________                                         No. of  No. of favorable                                                                            No. additional                                                                              Probability                                  segregating                                                                            alleles in Parents                                                                          favorable alleles in                                                                        that genotype                                loci (n)                                                                               (n/2)        new inbred   occurs*                                      ______________________________________                                         20      10           14           3 × 10.sup.-5                          24      12           16           2 × 10.sup.-5                          28      14           18           1 × 10.sup.-5                          32      16           20           8 × 10.sup.-6                          36      18           22           5 × 10.sup.-6                          40      20           24           3 × 10.sup.-6                          44      22           26           2 × 10.sup.-6                          48      24           28           1 × 10.sup.-6                          ______________________________________                                          *Probability that a useful combination exists, does not include the            probability of identifying this combination if it does exist.            

The possibility of having a usably high probability of being able to identify this genotype based on replicated field testing would be most likely smaller than this, and is a function of how large a population of genotypes is tested and how testing resources are allocated in the testing program.

SUMMARY OF THE INVENTION

According to the invention, there is provided a hybrid maize plant, designated as 32K61, produced by crossing two Pioneer Hi-Bred International, Inc. proprietary inbred maize lines; a first inbred maize line. This invention thus relates to the hybrid seed 32K61, the hybrid plant produced from the seed, and variants, mutants and trivial modifications of hybrid 32K61. This hybrid maize plant is characterized by good resistance to foliar leaf diseases. 32K61 has very good general plant health and late season intactness. 32K61 has good grain quality and high test weight. 32K61 gives consistent moderate yield with no major weaknesses in the hybrid.

DEFINITIONS

In the description and examples that follow, a number of terms are used herein. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided. NOTE: ABS is in absolute terms and %MN is percent of the mean for the experiments in which the inbred or hybrid was grown. These designators will follow the descriptors to denote how the values are to be interpreted. Below are the descriptors used in the data tables included herein.

ANT ROT=ANTHRACNOSE STALK ROT (Colletotrichum graminicola). A 1 to 9 visual rating indicating the resistance to Anthracnose Stalk Rot. A higher score indicates a higher resistance.

BAR PLT=BARREN PLANTS. The percent of plants per plot that were not barren (lack ears).

BRT STK=BRITTLE STALKS. This is a measure of the stalk breakage near the time of pollination, and is an indication of whether a hybrid or inbred would snap or break near the time of flowering under severe winds. Data are presented as percentage of plants that did not snap in paired comparisons and on a 1 to 9 scale (9=highest resistance) in Characteristics Charts.

BU ACR=YIELD (BUSHELSIACRE). Yield of the grain at harvest in bushels per acre adjusted to 15.5% moisture.

CLN=CORN LETHAL NECROSIS (synergistic interaction of maize chlorotic mottle virus (MCMV) in combination with either maize dwarf mosaic virus (MDMV-A or MDMV-B) or wheat streak mosaic virus (WSMV)). A 1 to 9 visual rating indicating the resistance to Corn Lethal Necrosis. A higher score indicates a higher resistance.

COM RST=COMMON RUST (Puccinia sorghi). A 1 to 9 visual rating indicating the resistance to Common Rust. A higher score indicates a higher resistance.

CRM=COMPARATIVE RELATIVE MATURITY (see PRM).

DID=DRYDOWN. This represents the relative rate at which a hybrid will reach acceptable harvest moisture compared to other hybrids on a 1-9 rating scale. A high score indicates a hybrid that dries relatively fast while a low score indicates a hybrid that dries slowly.

D/E=DROPPED EARS. Represented in a 1 to 9 scale in the Characteristics Chart, where 9 is the rating representing the least, or no, dropped ears.

DIP ERS=DIPLODIA EAR MOLD SCORES (Diplodia maydis and Diplodia macrospora). A 1 to 9 visual rating indicating the resistance to Diplodia Ear Mold. A higher score indicates a higher resistance.

DRP EAR=DROPPED EARS. A measure of the number of dropped ears per plot and represents the percentage of plants that did not drop ears prior to harvest.

D/T=DROUGHT TOLERANCE. This represents a 1-9 rating for drought tolerance, and is based on data obtained under stress conditions. A high score indicates good drought tolerance and a low score indicates poor drought tolerance.

EAR HT=EAR HEIGHT. The ear height is a measure from the ground to the highest placed developed ear node attachment and is measured in inches. This is represented in a 1 to 9 scale in the Characteristics Chart, where 9 is highest.

EAR MLD=General Ear Mold. Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant. This is based on overall rating for ear mold of mature ears without determining the specific mold organism, and may not be predictive for a specific ear mold.

EAR SZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher the rating the larger the ear size.

ECB 1LF=EUROPEAN CORN BORER FIRST GENERATION LEAF FEEDING (Ostrinia nubilalis). A 1 to 9 visual rating indicating the resistance to preflowering leaf feeding by first generation European Corn Borer. A higher score indicates a higher resistance.

ECB 21T=EUROPEAN CORN BORER SECOND GENERATION INCHES OF TUNNELING (Ostrinia nubilalis). Average inches of tunneling per plant in the stalk.

ECB 2SC=EUROPEAN CORN BORER SECOND GENERATION (Ostrinia nubilalis). A 1 to 9 visual rating indicating post flowering degree of stalk breakage and other evidence of feeding by European Corn Borer, Second Generation. A higher score indicates a higher resistance.

ECB DPE=EUROPEAN CORN BORER DROPPED EARS (Ostrinia nubilalis). Dropped ears due to European Corn Borer. Percentage of plants that did not drop ears under second generation corn borer infestation.

E/G=EARLY GROWTH. This represents a 1 to 9 rating for early growth, scored when two leaf collars are visible. A higher rating indicates a taller plant than does a lower rating.

EST CNT=EARLY STAND COUNT. This is a measure of the stand establishment in the spring and represents the number of plants that emerge on per plot basis for the inbred or hybrid.

EYE SPT=Eye Spot (Kabatiella zeae or Aureobasidium zeae). A 1 to 9 visual rating indicating the resistance to Eye Spot. A higher score indicates a higher resistance.

FUS ERS=FUSARIUM EAR ROT SCORE (Fusarium moniliforme or Fusarium subglutinans). A 1 to 9 visual rating indicating the resistance to Fusarium ear rot. A higher score indicates a higher resistance.

G/A=GRAIN APPEARANCE. Appearance of grain in the grain tank (scored down for mold, cracks, red streak, etc.).

GDU=Growing Degree Units. Using the Barger Heat Unit Theory, that assumes that maize growth occurs in the temperature range 50° F.-86° F. and that temperatures outside this range slow down growth; the maximum daily heat unit accumulation is 36 and the minimum daily heat unit accumulation is 0. The seasonal accumulation of GDU is a major factor in determining maturity zones.

GDU PHY=GDU TO PHYSIOLOGICAL MATURITY. The number of growing degree units required for an inbred or hybrid line to have approximately 50 percent of plants at physiological maturity from time of planting. Growing degree units are calculated by the Barger method.

GDU SHD=GDU TO SHED. The number of growing degree units (GDUs) or heat units required for an inbred line or hybrid to have approximately 50 percent of the plants shedding pollen and is measured from the time of planting. Growing degree units are calculated by the Barger Method, where the heat units for a 24-hour period are: ##EQU1##

The highest maximum temperature used is 86° F. and the lowest minimum temperature used is 50° F. For each inbred or hybrid it takes a certain number of GDUs to reach various stages of plant development.

GDU SLK=GDU TO SILK. The number of growing degree units required for an inbred line or hybrid to have approximately 50 percent of the plants with silk emergence from time of planting. Growing degree units are calculated by the Barger Method as given in GDU SHD definition.

GIB ERS=GIBBERELLA EAR ROT (PINK MOLD) (Gibberella zeae). A 1 to 9 visual rating indicating the resistance to Gibberella Ear Rot. A higher score indicates a higher resistance.

GLF SPT=Gray Leaf Spot (Cercospora zeae-maydis). A 1 to 9 visual rating indicating the resistance to Gray Leaf Spot. A higher score indicates a higher resistance.

GOS WLT=Goss' Wilt (Corynebacterium nebraskense). A 1 to 9 visual rating indicating the resistance to Goss' Wilt. A higher score indicates a higher resistance.

GRN APP=GRAIN APPEARANCE. This is a 1 to 9 rating for the general appearance of the shelled grain as it is harvested based on such factors as the color of harvested grain, any mold on the grain, and any cracked grain. High scores indicate good grain quality.

H/POP=YIELD AT HIGH DENSITY. Yield ability at relatively high plant densities on 1-9 relative rating system with a higher number indicating the hybrid responds well to high plant densities for yield relative to other hybrids. A 1, 5, and 9 would represent very poor, average, and very good yield response, respectively, to increased plant density.

HC BLT=HELMINTHOSPORIUM CARBONUM LEAF BLIGHT (Helminthosporium carbonum). A 1 to 9 visual rating indicating the resistance to Helminthosporium infection. A higher score indicates a higher resistance.

HD SMT=HEAD SMUT (Sphacelotheca reiliana). This score indicates the percentage of plants not infected.

INC DIA=GROSS INCOME (DOLLARS PER ACRE). Relative income per acre assuming drying costs of two cents per point above 15.5 percent harvest moisture and current market price per bushel.

INCOME/ACRE. Income advantage of hybrid to be patented over other hybrid on per acre basis.

INC ADV=GROSS INCOME ADVANTAGE. GROSS INCOME advantage of variety #1 over variety #2.

L/POP=YIELD AT LOW DENSITY. Yield ability at relatively low plant densities on a 1-9 relative system with a higher number indicating the hybrid responds well to low plant densities for yield relative to other hybrids. A 1, 5, and 9 would represent very poor, average, and very good yield response, respectively, to low plant density.

MDM CPX=MAIZE DWARF MOSAIC COMPLEX (MDMV=Maize Dwarf Mosaic Virus and MCDV=Maize Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating the resistance to Maize Dwarf Mosaic Complex. A higher score indicates a higher resistance.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture of the grain at harvest.

MST ADV=MOISTURE ADVANTAGE. The moisture advantage of variety #1 over variety #2 as calculated by: MOISTURE of variety #2 - MOISTURE of variety #1=MOISTURE ADVANTAGE of variety #1.

NLF BLT=Northern Leaf Blight (Helminthosporium turcicum or Exserohilum turcicum). A 1 to 9 visual rating indicating the resistance to Northern Leaf Blight. A higher score indicates a higher resistance.

PHY CRM=CRM at physiological maturity.

PLT HT=PLANT HEIGHT. This is a measure of the height of the plant from the ground to the tip of the tassel in inches. This is represented as a 1 to 9 scale, 9 highest, in the Characteristics Chart.

POL SC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount of pollen shed. The higher the score the more pollen shed.

POL WT=POLLEN WEIGHT. This is calculated by dry weight of tassels collected as shedding commences minus dry weight from similar tassels harvested after shedding is complete.

It should be understood that the inbred can, through routine manipulation of cytoplasmic or other factors, be produced in a male-sterile form. Such embodiments are also contemplated within the scope of the present claims.

POP K/A=PLANT POPULATIONS. Measured as 1000s per acre.

POP ADV=PLANT POPULATION ADVANTAGE. The plant population advantage of variety #1 over variety #2 as calculated by PLANT POPULATION of variety #2--PLANT POPULATION of variety #1=PLANT POPULATION ADVANTAGE of variety #1.

PRM=PREDICTED Relative Maturity. This trait, predicted relative maturity, is based on the harvest moisture of the grain. The relative maturity rating is based on a known set of checks and utilizes standard linear regression analyses and is referred to as the Comparative Relative Maturity Rating System that is similar to the Minnesota Relative Maturity Rating System.

PRM SHD=A relative measure of the growing degree units (GDU) required to reach 50% pollen shed. Relative values are predicted values from the linear regression of observed GDU's on relative maturity of commercial checks.

PRO=PROTEIN RATING. Rating on a 1 to 9 scale comparing relative amount of protein in the grain compared to hybrids of similar maturity. A "1" score difference represents a 0.4 point change in grain protein percent (e.g., 8.0% to 8.4%).

P/Y=PROTEIN/YIELD RATING. Indicates, on a 1 to 9 scale, the economic value of a hybrid for swine and poultry feeders. This takes into account the income due to yield, moisture and protein content.

ROOTS (%)=Percent of stalks NOT root lodged at harvest.

R/L=ROOT LODGING. A 1 to 9 rating indicating the level of root lodging resistance. The higher score represents higher levels of resistance.

RT LDG=ROOT LODGING. Root lodging is the percentage of plants that do not root lodge; plants that lean from the vertical axis as an approximately 30° angle or greater would be counted as root lodged.

RTL ADV=ROOT LODGING ADVANTAGE. The root lodging advantage of variety #1 over variety #2.

S/L=STALK LODGING. A 1 to 9 rating indicating the level of stalk lodging resistance. The higher scores represent higher levels of resistance.

SCT GRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount of scatter grain (lack of pollination or kernel abortion) on the ear. The higher the score the less scatter grain.

SDG VGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amount of vegetative growth after emergence at the seedling stage (approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure of the hybrid's worth based on information for up to five traits. A maize breeder may utilize his or her own set of traits for the selection index. One of the traits that is almost always included is yield. The selection index data presented in the tables represent the mean value averaged across testing stations.

SLF BLT=SOUTHERN LEAF BLIGHT (Helminthosporium maydis or Bipolaris maydis). A 1 to 9 visual rating indicating the resistance to Southern Leaf Blight. A higher score indicates a higher resistance.

SLK CRM=CRM at Silking.

SOU RST=SOUTHERN RUST (Puccinia polysora). A 1 to 9 visual rating indicating the resistance to Southern Rust. A higher score indicates a higher resistance.

STA GRN=STAY GREEN. Stay green is the measure of plant health near the time of black layer formation (physiological maturity). A high score indicates better late-season plant health.

STAND (%)=Percent of stalks standing at harvest.

STD ADV=STALK STANDING ADVANTAGE. The advantage of variety #1 over variety #2 for the trait STK CNT.

STK CNT=NUMBER OF PLANTS. This is the final stand or number of plants per plot.

STK LDG=STALK LODGING. This is the percentage of plants that did not stalk lodge (stalk breakage) as measured by either natural lodging or pushing the stalks and determining the percentage of plants that break below the ear.

STW WLT=Stewart's Wilt (Erwinia stewartii). A 1 to 9 visual rating indicating the resistance to Stewart's Wilt. A higher score indicates a higher resistance.

TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure the degree of blasting (necrosis due to heat stress) of the tassel at the time of flowering. A 1 would indicate a very high level of blasting at time of flowering, while a 9 would have no tassel blasting.

TAS SZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate the relative size of the tassel. The higher the rating the larger the tassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams) just prior to pollen shed.

TEX EAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate the relative hardness (smoothness of crown) of mature grain. A 1 would be very soft (extreme dent) while a 9 would be very hard (flinty or very smooth crown).

TIL LER=TILLERS. A count of the number of tillers per plot that could possibly shed pollen was taken. Data is given as a percentage of tillers: number of tillers per plot divided by number of plants per plot.

TST WT (CHARACTERISTICS CHART)=Test weight on a 1 to 9 rating scale with a 9 being the highest rating.

TST WT=TEST WEIGHT (UNADJUSTED). The measure of the weight of the grain in pounds for a given volume (bushel).

TST WTA=TEST WEIGHT ADJUSTED. The measure of the weight of the grain in pounds for a given volume (bushel) adjusted for 15.5 percent moisture.

TSW ADV=TEST WEIGHT ADVANTAGE. The test weight advantage of variety #1 over variety #2.

WIN M %=PERCENT MOISTURE WINS.

WIN Y %=PERCENT YIELD WINS.

YLD=YIELD. It is the same as BU ACR ABS.

YLD ADV=YIELD ADVANTAGE. The yield advantage of variety #1 over variety #2 as calculated by: YIELD of variety #1--YIELD variety #2=yield advantage of variety #1.

YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give a relative rating for yield based on plot ear piles. The higher the rating the greater visual yield appearance.

DETAILED DESCRIPTION OF THE INVENTION

Pioneer Brand Hybrid 32K61 expresses good resistance to Gray Leaf Spot in the maturity group and also has a good level of resistance to foliar leaf diseases. Hybrid 32K61 exhibits good grain quality and high test weight. The hybrid demonstrates general plant health and late season intactness and has the ability to outyield competition at low to moderate yield conditions. The hybrid has very few weaknesses, in fact its main weakness is that it may not consistently express high top yield levels under top end yield conditions. It has no other major weaknesses.

Pioneer Brand Hybrid 32K61 is a single cross, yellow endosperm, dent maize hybrid with good yield in its maturity. 32K61 has stable yield across environments and its overall;; combination of traits provides for excellent plant health.

This hybrid has the following characteristics based on the data collected primarily at Johnston, Iowa.

                                      TABLE 1                                      __________________________________________________________________________     VARIETY DESCRIPTION INFORMATION                                                VARIETY = 32K61                                                                __________________________________________________________________________       TYPE:                                                                          (describe intermediate types in Comments section):                           2     1 = Sweet 2 = Dent 3 = Flint 4 = Flour 5 = Pop 6 = Ornamental              MATURITY:                                                                        HEAT                                                                       DAYS                                                                               UNITS                                                                      075 1,355.0                                                                            From emergence to 50% of plants in silk                                075 1,355.0                                                                            From emergence to 50% of plants in pollen                              004 0,091.0                                                                            From 10% to 90% pollen shed                                            068 1,119.0                                                                            From 50% silk to harvest at 25% moisture                                 PLANT:                                                                                                            Standard                                                                            Sample                                                                    Deviation                                                                           Size                                 0,291.5                                                                            cm  Plant Height (to tassel tip) 12.02                                                                               2                                    0,112.0                                                                            cm  Ear Height (to base of top ear node)                                                                        0.00 2                                    0,019.5                                                                            cm  Length of Top Ear Internode  2.40 10                                   1       Average Number of Tillers    0.00 2                                    1.0     Average Number of Ears per Stalk                                                                            0.00 2                                    1.0     Anthocyanin of Brace Roots: 1 = Absent 2 = Faint 3 = Moderate                  4 = Dark                                                                 LEAF:                                                                                                             Standard                                                                            Sample                                                                    Deviation                                                                           Size                                 011.4                                                                              cm  Width of Ear Node Leaf       1.70 10                                   092.6                                                                              cm  Length of Ear Node Leaf      1.98 10                                   07.2    Number of leaves above top ear                                                                              0.00 10                                   043.5   Degrees Leaf Angle (measure from 2nd leaf above                                                             10.61                                                                               2                                            ear at anthesis to stalk above leaf)                                   03      Leaf Color         Dark Green                                                                            (Munsell code)                                                                        5GY44                                 1.5     Leaf Sheath Pubescence (Rate on scale from                                     1 = none to 9 = like peach fuzz)                                       7.0     Marginal Waves (Rate on scale from                                             1 = none to 9 = many)                                                  6.5     Longitudinal Creases (Rate on scale from                                       1 = none to 9 = many)                                                    TASSEL:                                                                                                           Standard                                                                            Sample                                                                    Deviation                                                                           Size                                 07.0    Number of Primary Lateral Branches                                                                          1.70 10                                   039.0   Branch Angle from Central Spike                                                                             9.90 2                                    70.5                                                                               cm  Tassel Length (from top leaf collar to tassel tip)                                                          0.14 2                                    8.0     Pollen Shed (rate on scale from 0 = male                                       sterile to 9 = heavy shed)                                             11      Anther Color       Pink   (Munsell code)                                                                        10R64                                 01      Glume Color        Light Green                                                                           (Munsell code)                                                                        5GY66                                 1.0     Bar Glumes (Glume Bands): 1 = Absent 2 = Present                       25      Peduncle Length (cm. from top leaf to basal branches)                  6a.                                                                              EAR (Unhusked Data):                                                         1       Silk Color (3 days Light Green                                                                           (Munsell code)                                                                        2.5GY96                                       after emergence)                                                       2       Fresh Husk Color   Medium Green                                                                          (Munsell code)                                                                        5GY66                                         (25 days after 50% silking)                                            21      Dry Husk Color (65 days after 50% silking)                                                        Buff   (Munsell code)                                                                        2.5Y8.54                              1       Position of Ear at Dry Husk Stage: 1 = Upright 2 = Horizontal 3 =              Pendant                          Upright                               5       Husk Tightness (Rate of Scale from 1 = very loose to 9 = very                  tight)                                                                 2       Husk Extension (at harvest): 1 = Short (ears exposed) 2 = Medium               (<8 cm)                                                                        3 = Long (8-10 cm beyond ear tip) 4 = Very Long (>10                                                            Medium                                6b.                                                                              EAR (Husked Ear Data):                                                                                            Standard                                                                            Sample                                                                    Deviation                                                                           Size                                 17  cm  Ear Length                   1.41 10                                   50  mm  Ear Diameter at mid-point    2.12 10                                   205 gm  Ear Weight                   36.77                                                                               10                                   19      Number of Kernel Rows        0.71 10                                   2       Kernel Rows: 1 = Indistinct 2 = Distinct                                                                        Distinct                              1       Row Alignment: 1 = Straight 2 = Slightly Curved 3                                                               Straight                              11  cm  Shank Length                 0.71 10                                   2       Ear Taper: 1 = Slight 2 = Average 3 = Extreme                                                                   Average                                 KERNEL (Dried):                                                                                                   Standard                                                                            Sample                                                                    Deviation                                                                           Size                                 14  mm  Kernel Length                0.71 10                                   7   mm  Kernel Width                 0.00 10                                   5   mm  Kernel Thickness             0.71 10                                   9       % Round Kernels (Shape Grade)                                                                               1.41 2                                    1       Aleurone Color Pattern: 1 = Homozygous 2 = Segregating                                                          Homo-                                                                          zygous                                7       Aluerone Color     Yellow (Munsell code)                                                                        2.5Y812                               7       Hard Endosperm Color                                                                              Yellow (Munsell code)                                                                        10YR714                               3       Endosperm Type:    Normal Starch                                               1 = Sweet (Su1) 2 = Extra Sweet (sh2) 3 = Normal Starch                        4 = High Amylose Starch 5 = Waxy Starch 6 = High Protein                       7 = High Lysine 8 = Super Sweet (se) 9 = High Oil                              10 = Other .sub.------                                                 32  gm  Weight per 100 Kernels (unsized sample)                                                                     1.41 2                                      COB:                                                                                                              Standard                                                                            Sample                                                                    Deviation                                                                           Size                                 27  mm  Cob Diameter at mid-point    1.41 10                                   14      Cob Color          Red    (Munsell code)                                                                        10R36                                         Cob Strength 1 = Weak 2 = Strong                                         DISEASE RESISTANCE                                                             (Rate from 1 (most susceptible) to 9 (most resistant); leave blank             if not tested; leave Race or Strain Options blank if polygenic):             A.  Leaf Blights, Wilts, and LocaI Infection Diseases                                Anthracnose Leaf Blight ( Colletotrichum graminicola)                    6     Common Rust (Puccinia sorghi)                                                  Common Smut (Ustilago                                                          maydis) Eyespot (Kabatiella zeae)                                        8     Goss's Wilt (Clavibacter michiganense spp. nebraskense)                  6     Gray Leaf Spot (Cercospora zeae-maydis)                                        Helminthosporium Leaf Spot (Bipolaris zeicola) Race .sub.------          5     Northern Leaf Blight ( Exserohilum turcicum) Race .sub.------            6     Southern Leaf Blight ( Bipolaris maydis) Race .sub.------                4     Southern Rust ( Puccinia polysora)                                       8     Stewart's Wilt (Erwinia stewartii)                                             Other (Specify) .sub.------                                              B.  Systemic Diseases                                                          7     Corn Lethal Necrosis (MCMV and MDMV)                                           Head Smut ( Sphacelotheca reiliana)                                            Maize Chlorotic Dwarf Virus (MDV)                                              Maize Chlorotic Mottle Virus (MCMV)                                      3     Maize Dwarf Mosaic Virus (MDMV)                                                Sorghum Downy Mildew of Corn (Peronosclerospora sorghi)                        Other (Specify) .sub.------                                              C.  Stalk Rots                                                                 5     Anthracnose Stalk Rot ( Colletotrichum graminicola)                            Diplodia Stalk Rot (Stenocarpella maydis)                                      Fusarium Stalk Rot (Fusarium moniliforme)                                      Gibberella Stalk Rot (Gibberella zeae)                                         Other (Specify) .sub.------                                              D.  Ear and Kernel Rots                                                              Aspergillus Ear and Kernel Rot ( Aspergillus flavus)                     5     Diplodia Ear Rot (Stenocarpella maydis)                                  5     Fusarium Ear and Kernel Rot (Fusarium moniliforme)                             Gibberella Ear Rot (Gibberella zeae)                                           Other (Specify) .sub.------                                                    Banks grass Mite ( Oligonychus pratensis)                                      Corn Worm (Helicoverpa zea)                                                    Leaf Feeding                                                                   Silk Feeding                                                                   mg larval wt.                                                                  Ear Damage                                                                     Corn Leaf Aphid (Rhopalosiphum maidis)                                         Corn Sap Beetle (Carpophilus dimidiatus                                        European Corn Borer (Ostrinia nubilalis)                                 6     1st Generation (Typically Whorl Leaf Feeding)                            5     2nd Generation (Typically Leaf Sheath-Collar Feeding)                          Stalk Tunneling                                                                cm tunneled/plant                                                              Fall Armyworm (Spodoptera fruqiperda)                                          Leaf Feeding                                                                   Silk Feeding                                                                   mg larval wt.                                                                  Maize Weevil (Sitophilus zeamaize                                              Northern Rootworm (Diabrotica barberi)                                         Southern Rootworm (Diabrotica undecimpunctata)                                 Southwestern Corn Borer (Diatreaea grandiosella)                               Leaf Feeding                                                                   Stalk Tunneling                                                                cm tunneled/plant                                                              Two-spotted Spider Mite (Tetranychus urticae)                                  Western Rootworm (Diabrotica virgifrea virgifera)                              Other (Specify) .sub.------                                                AGRONOMIC TRAITS:                                                            6       Staygreen (at 65 days after anthesis)                                          (Rate on a scale from 1 = worst to excellent)                          1.0     % Dropped Ears (at 65 days after anthesis)                                     % Pre-anthesis Brittle Snapping                                                % Pre-anthesis Root Lodging                                            6.7     Post-anthesis Root Lodging (at 65 days after anthesis)                 11,140  Kg/ha Yield (at 12-13% grain moisture)                                 __________________________________________________________________________

Research Comparisons for Pioneer Hybrid 32K61

Comparisons of characteristics of Pioneer Brand Hybrid 32K61 were made against Pioneer Brand Hybrids 3163, 3245, and 3335 all of which are similarly adapted.

Table 2A compares Pioneer Hybrid 32K61 and Pioneer Hybrid 3163, another similarly adapted line. The results show that 32K61 is significantly lower yielding but has significantly lower harvest moisture and a signficantly higher test weight than hybrid 3163. The 32K61 hybrid also exhibits a significantly higher seedling vigor score and significantly higher resistance to root lodging than the 3163 hybrid. 32K61 demonstrates significantly superior stalk lodging resistance, a significantly better grain appearance score and is taller with lower ear placement than hybrid 3163. The 32K61 hybrid demonstrates significantly superior resistance to both Gray Leaf Spot, and to Stewart's Wilt than hybrid 3163.

Table 2B compares Pioneer Hybrid 32K61 and Pioneer Hybrid 3245. The results show that hybrid 32K61 exhibits a significantly superior stay green score and demonstrates significantly better resistance to stalk lodging than the 3245 hybrid. The 32K61 hybrid also demonstrates a significantly superior resistance to Gray Leaf Spot, Northern Leaf Blight, Southern Leaf Blight, Anthracnose Stalk Rot and Southern Rust than hybrid 3245.

Table 2C compares Pioneer Hybrid 32K61 with Pioneer Hybrid 3335. The results show that hybrid 32K61 is lower yielding but exhibits a significantly higher test weight than hybrid 3335. Hybrid 32K61 also demonstrates significantly superior stay green score and significantly higher resistance to stalk lodging than hybrid 3335. Hybrid 32K61 also exhibits a significantly superior grain appearance score and significantly higher resistance to Gray Leaf Spot, Stewart's Wilt, and Anthracnose Stalk Rot than hybrid 3335. Both hybrids exhibit above average seedling vigor.

                                      TABLE 2A                                     __________________________________________________________________________     HYBRID COMPARISON REPORT                                                       VARIETY #1 = 32K61                                                             VARIETY #2 = 3163                                                              __________________________________________________________________________              PRM  BU   BU        TST  SDG  EST  GDU                                TOTAL                                                                              PRM  SHD  ACR  ACR  MST  WT   VGR  CNT  SHD                                SUM ABS  ABS  ABS  % MN % MN ABS  % MN % MN % MN                               __________________________________________________________________________     1   114  116  175.2                                                                               103  99   58.2 105  99   104                                2   118  116  182.5                                                                               107  107  55.3 96   102  104                                LOCS                                                                               133  33   738  738  770  189  82   140  42                                 REPS                                                                               133  33   767  767  799  193  97   149  48                                 DIFF                                                                               4    0    7.3  4    8    2.9  9    3    0                                  PR > T                                                                             .000#                                                                               .999 .000#                                                                               .000#                                                                               .000#                                                                               .000#                                                                               .002#                                                                               .000#                                                                               .999                               __________________________________________________________________________         GDU  STK  PLT  EAR  RT   STA  STK  BRT  GRN                                TOTAL                                                                              SLK  CNT  HT   HT   LDG  GRN  LDG  STK  APP                                SUM % MN % MN % MN % MN % MN % MN % MN % MN % MN                               __________________________________________________________________________     1   105  99   103  96   104  109  105  100  111                                2   105  100  100  101  93   120  100  97   98                                 LOCS                                                                               33   689  110  191  86   113  277  11   15                                 REPS                                                                               33   742  124  205  87   137  290  13   15                                 DIFF                                                                               0    1    2    5    11   11   5    3    13                                 PR > T                                                                             .999 .007#                                                                               .000#                                                                               .000#                                                                               .007#                                                                               .001#                                                                               .000#                                                                               .322 .042+                              __________________________________________________________________________         DRP  GLF  NLF  SLF  STW  MDM  FUS  DIP  COM                                TOTAL                                                                              EAR  SPT  BLT  BLT  WLT  CPX  ERS  ERS  RST                                SUM % MN ABS  ABS  ABS  ABS  ABS  ABS  ABS  ABS                                __________________________________________________________________________     1   100  5.6  5.0  6.0  8.0  2.8  6.4  5.0  6.0                                2   100  4.0  6.3  6.0  6.0  3.5  4.8  6.0  5.0                                LOCS                                                                               153  16   1    1    2    2    5    1    1                                  REPS                                                                               155  16   3    1    2    4    5    1    1                                  DIFF                                                                               0    1.6  1.3  0.0  2.0  0.8  1.6  1.0  1.0                                PR > T                                                                             .999 .000#          .000#                                                                               .500 .120                                         __________________________________________________________________________         SOU  ECB  ECB                                                              TOTAL                                                                              RST  DPE  2SC                                                              SUM ABS  ABS  ABS                                                              __________________________________________________________________________     1   6.0  98.0 4.6                                                              2   4.0  100.0                                                                               5.4                                                              LOCS                                                                               1    1    8                                                                REPS                                                                               1    1    8                                                                DIFF                                                                               2.0  2.0  0.8                                                              PR > T        .222                                                             __________________________________________________________________________      * = 10% SIG                                                                    + = 5% SIG                                                                     # = 1% SIG                                                               

                                      TABLE 2B                                     __________________________________________________________________________     HYBRID COMPARISON REPORT                                                       VARIETY #1 = 32K61                                                             VARIETY #2 = 3245                                                              __________________________________________________________________________              PRM  BU   BU        TST  SDG  EST  GDU                                TOTAL                                                                              PRM  SHD  ACR  ACR  MST  WT   VGR  CNT  SHD                                SUM ABS  ABS  ABS  % MN % MN ABS  % MN % MN % MN                               __________________________________________________________________________     1   114  116  171.5                                                                               103  100  58.0 104  97   104                                2   114  114  173.1                                                                               103  100  57.8 108  103  101                                LOCS                                                                               61   36   253  253  256  122  106  113  46                                 REPS                                                                               61   36   291  291  294  128  127  122  54                                 DIFF                                                                               0    3    1.6  1    0    0.2  4    6    2                                  PR > T                                                                             .999 .000#                                                                               .312 .424 .999 .197 .211 .000#                                                                               .000#                              __________________________________________________________________________         GDU  STK  PLT  EAR  RT   STA  STK  BRT  GRN                                TOTAL                                                                              SLK  CNT  HT   HT   LDG  GRN  LDG  STK  APP                                SUM % MN % MN % MN % MN % MN % MN % MN % MN % MN                               __________________________________________________________________________     1   104  99   103  99   107  120  106  101  107                                2   103  102  99   97   100  98   98   101  105                                LOCS                                                                               36   286  113  117  66   130  146  14   27                                 REPS                                                                               38   357  131  135  84   153  172  20   27                                 DIFF                                                                               1    3    5    3    7    21   8    0    2                                  PR > T                                                                             .000#                                                                               .000#                                                                               .000#                                                                               .002#                                                                               .180 .000#                                                                               .000#                                                                               .999 .617                               __________________________________________________________________________         DRP  GLF  NLF  SLF  GOS  STW  ANT  HD                                      TOTAL                                                                              EAR  SPT  BLT  BLT  WLT  WLT  ROT  SMT  CLN                                SUM % MN ABS  ABS  ABS  ABS  ABS  ABS  ABS  ABS                                __________________________________________________________________________     1   99   5.9  5.1  6.0  8.0  8.0  4.8  100.0                                                                               6.5                                2   100  4.0  3.2  4.6  8.0  4.5  2.7  97.5 5.5                                LOCS                                                                               35   36   10   6    2    2    6    2    2                                  REPS                                                                               38   50   21   11   4    2    12   6    4                                  DIFF                                                                               1    1.9  1.9  1.4  0.0  3.5  2.2  2.5  1.0                                PR > T                                                                             .402 .000#                                                                               .000#                                                                               .003#                                                                               .999 .090*                                                                               .001#                                                                               .083*                                                                               .705                               __________________________________________________________________________         MDM  FUS  DIP  COM  SOU  ECB  ECB                                          TOTAL                                                                              CPX  ERS  ERS  RST  RST  DPE  2SC                                          SUM ABS  ABS  ABS  ABS  ABS  ABS  ABS                                          __________________________________________________________________________     1   2.9  5.3  4.8  5.5  4.0  98.0 4.7                                          2   2.6  5.6  4.5  4.0  2.5  96.2 4.8                                          LOCS                                                                               4    8    2    2    2    1    11                                           REPS                                                                               10   11   3    3    4    1    14                                           DIFF                                                                               0.4  0.3  0.3  1.5  1.5  1.8  0.1                                          PR > T                                                                             .058*                                                                               .558 .874 .205 .000#     .889                                         __________________________________________________________________________      * = 10% SIG                                                                    + = 5% SIG                                                                     # = 1% SIG                                                               

                                      TABLE 2C                                     __________________________________________________________________________     HYBRID COMPARISON REPORT                                                       VARIETY #1 = 32K61                                                             VARIETY #2 = 3335                                                              __________________________________________________________________________              PRM  BU   BU        TST  SDG  EST  GDU                                TOTAL                                                                              PRM  SHD  ACR  ACR  MST  WT   VGR  CNT  SHD                                SUM ABS  ABS  ABS  % MN % MN ABS  % MN % MN % MN                               __________________________________________________________________________     1   114  116  175.1                                                                               102  104  57.3 103  98   105                                2   113  113  183.0                                                                               107  101  56.0 105  99   101                                LOCS                                                                               203  42   959  959  983  340  109  196  52                                 REPS                                                                               203  42   1051 1051 1078 364  140  233  65                                 DIFF                                                                               1    3    7.9  5    3    1.3  2    1    4                                  PR > T                                                                             .000#                                                                               .000#                                                                               .000#                                                                               .000#                                                                               .000#                                                                               .000#                                                                               .364 .106 .000#                              __________________________________________________________________________         GDU  STK  PLT  EAR  RT   STA  STK  BRT  GRN                                TOTAL                                                                              SLK  CNT  HT   HT   LDG  GRN  LDG  STK  APP                                SUM % MN % MN % MN % MN % MN % MN % MN % MN % MN                               __________________________________________________________________________     1   105  99   103  98   106  129  105  101  113                                2   101  100  99   95   110  103  94   100  86                                 LOCS                                                                               38   1033 224  239  88   146  495  11   17                                 REPS                                                                               43   1152 253  268  104  171  527  17   17                                 DIFF                                                                               4    1    4    3    4    26   11   2    27                                 PR > T                                                                             .000#                                                                               .000#                                                                               .000#                                                                               .000#                                                                               .129 .000#                                                                               .000#                                                                               .579 .003#                              __________________________________________________________________________         DRP  GLF  NLF  SLF  GOS  STW  ANT  HD                                      TOTAL                                                                              EAR  SPT  BLT  BLT  WLT  WLT  ROT  SMT  CLN                                SUM % MN ABS  ABS  ABS  ABS  ABS  ABS  ABS  ABS                                __________________________________________________________________________     1   100  5.7  5.1  6.0  8.0  8.0  4.8  100.0                                                                               6.5                                2   100  4.6  4.6  5.4  8.0  7.0  3.1  100.0                                                                               5.8                                LOCS                                                                               279  40   10   5    2    2    6    2    2                                  REPS                                                                               286  63   21   10   4    2    12   6    4                                  DIFF                                                                               0    1.1  0.5  0.6  0.0  1.0  1.8  0.0  0.8                                PR > T                                                                             .999 .000#                                                                               .174 .178 .999 .000#                                                                               .003#                                                                               .999 .656                               __________________________________________________________________________         MDM  FUS  DIP  COM  SOU  ECB  ECB  ECB                                     TOTAL                                                                              CPX  ERS  ERS  RST  RST  DPE  1LF  2SC                                     SUM ABS  ABS  ABS  ABS  ABS  ABS  ABS  ABS                                     __________________________________________________________________________     1   2.9  4.6  4.8  5.0  4.7  98.0 6.0  5.3                                     2   4.3  4.5  3.0  5.5  4.3  100.0                                                                               3.0  4.7                                     LOCS                                                                               4    5    2    1    3    1    1    15                                      REPS                                                                               10   8    3    2    5    1    1    18                                      DIFF                                                                               1.4  0.1  1.8  0.5  0.3  2.0  3.0  0.7                                     PR > T                                                                             .010+                                                                               .932 .258      .423           .182                                    __________________________________________________________________________      * = 10% SIG                                                                    += 5% SIG                                                                      # = 1% SIG                                                               

Strip Test Data for Hybrid 32K61

Comparison data was collected from strip tests that were grown by farmers. Each hybrid was grown in strips of 4, 6, 8, 12, etc. rows in fields depending on the size of the planter used. The data was collected from strip tests that had the hybrids in the same area and weighed. The moisture percentage was determined and bushels per acre was adjusted to 15.5 percent moisture. The number of comparisons represent the number of locations or replications for the two hybrids that were grown in the same field in close proximity and compared.

Comparison strip testing was done between Pioneer Brand Hybrid 32K61 and Pioneer Brand Hybrids 3335, 3245, 3394, and 3163. The comparisons come from all the hybrid's adapted growing areas in the United States.

These results are presented in Table 3. As can be seen from the results, hybrid 32K61 has a advantage for stand and roots overall of the hybrids. It also demonstrates superior test weight compared to all other hybrids. The test weight advantages was 1.3 pounds per bushel. 32K61 exhibits a yield and income advantage over one of the hybrids, however its lack of yield and income advantage is countered by its advantages for other important traits such as roots, stand and test weight which will make it an important addition for most of the areas where these hybrids are grown.

    __________________________________________________________________________     1996 PERFORMANCE COMPARISON REPORT FOR CORN                                    1 YEAR SUMMARY OF ALL STANDARD TEST TYPES                                                        Income/                                                                             Pop Stand                                                                             Roots                                                                              Test                                         Brand Product                                                                             Yield                                                                              Moist                                                                             Acre K/Acre                                                                             (%)                                                                               (%) Wt                                           __________________________________________________________________________     PIONEER                                                                              32K61                                                                               169.2                                                                              23.2                                                                              481.97                                                                              24.7                                                                               95 99  57.4                                         PIONEER                                                                              3335 173.7                                                                              22.1                                                                              498.42                                                                              25.3                                                                               90 99  56.1                                         Advantage  -4.5                                                                               -1.1                                                                              -16.45                                                                              -0.6                                                                               5  0   1.3                                          Number of Comparisons                                                                     417 417                                                                               417  266 201                                                                               149 354                                          Percent Wins                                                                              39  24 36   30  61 6   77                                           Probability of Difference                                                                 99  99 99   99  99 62  99                                           PIONEER                                                                              32K61                                                                               169.2                                                                              19.8                                                                              492.74                                                                              24.3                                                                               96 99  58.6                                         PIONEER                                                                              3245 167.2                                                                              19.8                                                                              487.23                                                                              24.1                                                                               95 97  58.6                                         Advantage  2.0 0.0                                                                               5.51 0.2 1  2   0.0                                          Number of Comparisons                                                                     133 133                                                                               133  109 79 56  122                                          Percent Wins                                                                              54  42 53   44  35 14  44                                           Probability of Difference                                                                 87  48 86   75  97 90  54                                           PIONEER                                                                              32K61                                                                               163.3                                                                              19.8                                                                              473.66                                                                              24.3                                                                               96 99  58.7                                         PIONEER                                                                              3163 162.9                                                                              21.5                                                                              466.68                                                                              24.1                                                                               91 98  55.9                                         Advantage  0.4 1.7                                                                               6.98 0.2 5  1   2.8                                          Number of Comparisons                                                                     214 214                                                                               214  136 94 68  185                                          Percent Wins                                                                              50  75 53   44  60 8   92                                           Probability of Difference                                                                 24  99 95   72  99 49  99                                           PIONEER                                                                              32K61                                                                               166.7                                                                              21.9                                                                              478.50                                                                              24.6                                                                               95 99  57.9                                         WEIGHTED AVG                                                                              168.6                                                                              21.6                                                                              484.83                                                                              24.7                                                                               91 98  56.6                                         Advantage  -1.9                                                                               -0.3                                                                              -6.33                                                                               -0.1                                                                               4  1   1.3                                          Number of Comparisons                                                                     819 819                                                                               819  556 410                                                                               297 714                                          Percent Wins                                                                              45  39 44   38  55 10  72                                           Probability of Difference                                                                 99  99 99   75  99 96  99                                           __________________________________________________________________________      NOTE:                                                                          The probability values are useful in analyzing if there is a "real"            difference in the genetic potential of the products involved. High values      are desirable, with 95% considered significant for real differences.     

NOTE: The probability values are useful in analyzing if there is a "real" difference in the genetic potential of the products involved. High values are desirable, with 95% considered significant for real differences.

Comparison of Key Characteristics for Hybrid 32K61

Characteristics of Pioneer Hybrid 32K61 are compared to Pioneer Hybrids 3163, 3245,and 3335 in Table 4. The values given for most traits are on a 1-9 basis. In these cases 9 would be outstanding, while 1 would be poor for the given characteristics. Table 4 shows that hybrid 32K61 demonstrates excellent yield. Hybrid 32K61 exhibits superior stalk lodging resistance, superior Gray Leaf spot resistance superior root lodging resistance than all of the hybrids compared. It also demonstrates very good stay green, test weight and drydown. Hybrid 32K61's good consistent yield combined with its other favorable agronomic characteristics should make it an important hybrid to its area of adaptation.

                                      TABLE 4                                      __________________________________________________________________________     Hybrid Patent Comparisons-Characteristics                                      Pioneer Hybrid 32K61 vs. Pioneer Hybrids 3163, 3245 and                        __________________________________________________________________________     3335                                                                                   SILK                                                                               PHY                                                                               GDU                                                                               GDU            STA   TST                                     VARIETY                                                                             CRM                                                                               CRM CRM                                                                               SILK                                                                              PHY                                                                               YLD                                                                               D/D                                                                               S/L                                                                               R/L                                                                               GRN                                                                               D/F                                                                               WT                                      __________________________________________________________________________     32K61                                                                               114                                                                               116 114                                                                               1450                                                                              2770                                                                              9  7  8  8  8  7  8                                       3163 119                                                                               117 118                                                                               1460                                                                              2870                                                                              9  7  4  6  8  7  4                                       3245 115                                                                               115 114                                                                               1440                                                                              2770                                                                              8  6  5  4  5  5  8                                       3335 113                                                                               113 114                                                                               1410                                                                              2770                                                                              9  7  4  7  7  6  6                                       __________________________________________________________________________             PLT EAR   BRT                                                                               HSK                                                                               GLF                                                                               NLF                                                                               SLF                                                                               GOS                                                                               STW                                                                               ANT                                     VARIETY                                                                             E/G                                                                               HT  HT D/E                                                                               STK                                                                               CV SPT                                                                               BLT                                                                               BLT                                                                               WLT                                                                               WLT                                                                               ROT                                     __________________________________________________________________________     32K61                                                                               6  7   6  5  3  5  6  5  7  8  8  5                                       3163 6  5   6  5  3  4  4  6  7  8  4  4                                       3245 5  6   4  5  6  5  4  2  5  8  5  4                                       3335 5  7   5  6  3  3  5  4  5  9  6  3                                       __________________________________________________________________________             MDM FUS                                                                               COM                                                                               SOU                                                                               ECB                                                       VARIETY                                                                             CLN                                                                               CPX ERS                                                                               RST                                                                               RST                                                                               2SC                                                       __________________________________________________________________________     32K61                                                                               7  3   5  5  4  5                                                         3163 4  4   5  5  3  5                                                         3245 5  3   6  4  2  4                                                         3335 5  4   4  6  3  4                                                         __________________________________________________________________________

INDUSTRIAL APPLICABILITY

This invention includes hybrid maize seed of 32K61 and the hybrid maize plant produced therefrom. The foregoing was set forth by way of example and is not intended to limit the scope of the invention.

As used herein, the term plant includes plant cells, plant protoplasts, plant cell tissue cultures from which maize plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants, or parts of plants, such as embryos, pollen, ovules, flowers, kernels, ears, cobs, leaves, seeds, husks, stalks, roots, root tips, anthers, silk and the like.

Duncan, Williams, Zehr, and Widholm, Planta, (1985) 165:322-332 reflects that 97% of the plants cultured which produced callus were capable of plant regeneration. Subsequent experiments with both inbreds and hybrids produced 91% regenerable callus which produced plants. In a further study in 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988), 7:262-265 reports several media additions which enhance regenerability of callus of two inbred lines. Other published reports also indicated that "nontraditional" tissues are capable of producing somatic embryogenesis and plant regeneration. K. P. Rao, et al., Maize Genetics Cooperation Newsletter, 60:64-65 (1986), refers to somatic embryogenesis from glume callus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345-347 (1987) indicates somatic embryogenesis from the tissue cultures of maize leaf segments. Thus, it is clear from the literature that the state of the art is such that these methods of obtaining plants are, and were, "conventional" in the sense that they are routinely used and have a very high rate of success.

Tissue culture of maize is described in European Patent Application, publication 160,390, incorporated herein by reference. Maize tissue culture procedures are also described in Green and Rhodes, "Plant Regeneration in Tissue Culture of Maize," Maize for Biological Research (Plant Molecular Biology Association, Charlottesville, Va. 1982, at 367-372) and in Duncan, et al., "The Production of Callus Capable of Plant Regeneration from Immature Embryos of Numerous Zea Mays Geneotypes," 165 Planta 322-332 (1985). Thus, another aspect of this invention is to provide cells which upon growth and differentiation produce maize plants having the genotype of 32K61.

Maize is used as human food, livestock feed, and as raw material in industry. The food uses of maize, in addition to human consumption of maize kernels, include both products of dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is also used extensively as livestock feed, primarily for beef cattle, dairy cattle, hogs, and poultry.

Industrial uses of maize include production of ethanol, maize starch in the wet-milling industry and maize flour in the dry-milling industry. The industrial applications of maize starch and flour are based on functional properties, such as viscosity, film formation, adhesive properties, and ability to suspend particles. The maize starch and flour have application in the paper and textile industries. Other industrial uses include applications in adhesives, building materials, foundry binders, laundry starches, explosives, oil-well muds, and other mining applications.

Plant parts other than the grain of maize are also used in industry. Stalks and husks are made into paper and wallboard and cobs are used for fuel and to make charcoal.

The seed of the hybrid maize plant and various parts of the hybrid maize plant can be utilized for human food, livestock feed, and as a raw material in industry.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the invention, as limited only by the scope of the appended claims. 

What is claimed is:
 1. Hybrid maize seed designated 32K61, representative seed of said hybrid 32K61 having been deposited under ATCC accession number
 209725. 2. A maize plant, or its parts, produced by the seed of claim
 1. 3. Pollen of the plant of claim
 2. 4. An ovule of the plant of claim
 2. 5. A tissue culture of regenerable cells of a hybrid maize plant 32K61, representative seed of said hybrid maize plant 32K61 having been deposited under ATCC accession number 209725, wherein the tissue regenerates plants capable of expressing all the morphological and physiological characteristics of said hybrid maize plant 32K61.
 6. A tissue culture according to claim 5, the cells or protoplasts being from a tissue selected from the group consisting of leaves, pollen, embryos, roots, root tips, anthers, silks, flowers, kernels, ears, cobs, husks, and stalks.
 7. A maize plant, or its parts, regenerated from the tissue culture of claim 5 and capable of expressing all the morphological and physiological characteristics of hybrid maize plant 32K61, representative seed having been deposited under ATCC accession number
 209725. 